This single‐arm, repeated measures study investigated the impact caregiver trauma history may have on treatment response following an intensive, 2‐day Emotion Focused Family Therapy (EFFT) caregiver workshop. Caregivers (n = 243) completed questionnaires regarding their child's emotion regulation and clinical symptoms, as well as their own childhood trauma history (i.e., exposure to various forms of child maltreatment), caregiver self‐efficacy and caregiver blocks (e.g., fears) to support their child's treatment and recovery. Questionnaires were administered prior to and immediately following the workshop and again 4, 8 and 12 months later. At baseline, caregivers who reported experiences of childhood maltreatment demonstrated more blocks compared with caregivers who did not (B = 6.35, SE = 2.62, p < 0.05). Results indicated that caregivers with and without maltreatment histories reported similar, significant gains in their child's total difficulties (B = 0.64, SE = 0.41, p = 0.12) and emotional negativity and lability (B = 0.51, SE = 0.48, p = 0.29) at 12‐month post‐workshop. Caregivers with maltreatment histories reported greater improvements in caregiver blocks (B = 5.15, SE = 1.34, p < 0.001) and child emotion regulation (B = 0.90, SE = 0.18, p < 0.001) than caregivers without maltreatment histories. They also report less, but still significant, improvement in parental self‐efficacy (B = −0.68, SE = 0.26, p < 0.01) when compared with caregivers without maltreatment histories. Findings suggest that EFFT workshops may be an acceptable and effective trans‐diagnostic intervention for families presenting with complex histories, including caregiver exposure to childhood maltreatment.